I'm 22 and low on cash and knowledge, but want to make my system better. I have collected a bunch of cheap pieces of the years (Bar Mitzvah presents, scavenged, etc.), and am trying to figure out how to best combine them. I was hoping you all might be able to make sense of what I have if I list all my components. My first priority is that is it sound good with my turntable.

Here is a list of my components. Keep in mind that not all of it is currently hooked up - I have to make a choice of what to use and what to trash/sell.

Receivers:
Kenwood VR - 605

JVC RX330VB. 2 Channels. 250W. Inherited it from my dad when he got one of those HT in a box deals.

Turntables:
Marantz 6170 DD Grado Black cartridge
Technics SL-220 Belt drive (would use the same cart)
I'm basically decided hear - the Marantz is the better table. But I listed them both in hopes of sparking a DD v. belt drive argument .

Pre-Amp:
Radio Shack (the $30 unit that runs via 9-volt battery)

Subwoofer:
Yamaha YST-SW45 subwoofer.


Speakers:
Marantz RG150's: Big-ss floor speakers that I also scavenged from my father's old system. They've got 12" subs, 4" liquid cooled midrange, and 3" liquid cooled tweeter. They'll hold 8 OHMs.

Bose 101's: Little speakers I got for free when the previous owner of our house didn't bother to move them. They sell for about $100 I believe. They say they handle 4 OHM's

Bose 100's: First speakers. Pretty crappy little guys. It registers bass by making a horrible plastic death rattle. The only thing I was pondering was whether they merited packing with non-hardening clay.

JBL TLX Movie surround - My first surround sound setup. Has a center box, which I currently use, and two surround speakers, which I do not. They say they handle 8 OHM's.

So, what should I use, and what is total garbage? I know ultimately I'm going to just have to start swapping things around to see what works, but I want an educated starting point. For instance, does it matter that the Bose have a 4 OHM impedance, and the other speakers 8? What does that even mean?

I'd appreciate any advice you guys have to offer.